1. Field of the Invention
This invention relates to a process for producing hexafluoroacetone hydrate, and more particularly to a process for producing hexafluoroacetone hydrate from hexafluoro-.alpha.-hydroxyisobutanoic acid.
2. Description of the Prior Art
Hexafluoroacetone is a monomer for producing a synthetic resin, a synthetic rubber, etc., or is used as an intermediate for cross-linking agents such as bisphenol AF, etc., or an intermediate raw material for medicaments, agricultural chemicals, etc.
The following processes have been so far proposed for producing hexafluoroacetone hydrate having the said applications. ##STR1##
However, the foregoing processes have the following disadvantages.
(1) Oxidation reaction by potassium permanganate proceeds vigorously and the by-produced manganese dioxide is an industrial waste which is hard to treat. PA1 (2) High purity oxide is hard to synthesize from hexafluoropropene and thus the produced hexafluoroacetone contains hexafluoropropene, etc. PA1 (3) In the oxidation of hexafluorothioacetone dimer by nitric acid, the produced hexafluoroacetone hydrate contains NO.sub.2 and SO.sub.2, whose removed is troublesome. PA1 (4) In the use of hexachloroacetone, chlorine not only contributes to increase the weight, but also is synthetically not efficient, and furthermore toxic antimony pentachloride is required. Thus, a high purity product is hard to obtain.